A propagating radio frequency (RF) signal can have different polarizations, namely linear, elliptical, or circular. Linear polarization consists of vertical polarization and horizontal polarization, whereas circular polarization consists of left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP). An antenna is typically configured to pass one polarization, such as LHCP, and reject the other polarization, such as RHCP.
Conventional very small aperture terminal (VSAT) antennas utilize a fixed polarization that is generally hardware dependant. During installation of the satellite terminal, the basis polarization is generally set and the polarizer is fixed in position. Changing this setting generally requires a technician at the terminal to physically manipulate the polarizer.
Unlike a typical single polarization antenna, some devices are configured to change polarizations without disassembling the antenna terminal. As an example and with reference to FIG. 1, a prior embodiment is the use of “baseball” switches 101 to provide electronically commandable switching between polarizations. As can be understood by the block diagram, the rotation of the “baseball” switches 101, by connecting one signal path and terminating the other signal path, cause a change in polarization. A separate rotational actuator with independent control circuitry is generally required for each “baseball” switch 101, which increases the cost of device.
Thus, there is a need for a new low cost method and device for switching polarization of an antenna system that results in low loss and high power performance. Also, there is a need for remote substantially instantaneous switching polarization of an antenna systems.